1. Field of the Invention
This invention relates generally to metal forming machines, and more particularly, relates to multiple plunger power presses such as cam eyelet machines and the like, suitable for automatically producing shells and other formed parts. The invention represents an improvement over prior U.S. Pat. No. 3,369,387.
A cam eyelet machine is utilized to shape metal blanks by such consecutive operations as drawing, bottom or side piercing, fluting, flange flattening, resizing, dimpling, clipping, etc. Special devices can also be added to permit the accomplishment of such operations as lettering, heading, and threading. Generally, the metal blanks, which are shaped by the machine, are cut by the machine from a strip of metal fed from a reel. The reel is usually positioned in front of the first or blanking plunger so that the strip passes directly over the blanking die through a roll feed and is finally wound on a scrap reel at the rear of the machine.
2. Prior Art
A cam eyelet machine, as disclosed in U.S. Pat. No. 3,369,387, for example, includes a first cam shaft 60 connected to be driven through a series of belts and pulleys from a motor 50. A transfer shaft or side shaft 71 is engaged through bevelled gears 70A and 70B with the first cam shaft 60, to be driven at one end from the first cam shaft, and has a bevel 73A on its other end engaged with a corresponding bevel gear 73B on a second cam shaft 65, to drive the second cam shaft. Additionally, the side shaft or transfer shaft 71 has a cam 93 between its ends for cooperation with transfer slide 90 which is reciprocable in frame 11. Side shaft 71 carries the load of the transfer mechanism, the blank hold down load and the knock-up or knockout load. In the event any of these loads exceeds a certain stress, severe damage can occur to the machine.